The venous drainage of the tectum mesencephali. An anatomical angiographic study of the quadrigeminal veins

The normal course and appearance of the veins draining the tectum mesencephali proper are described in detail on the basis of the anatomical radiological study. These specific veins, the quadrigeminal veins, were constantly present on autopsy study. There are two types of variations of these quadrigeminal veins. They have a close anatomical and angiographic correlation with the quadrigeminal plate proper, and also outline the posterior aspects of the quadrigeminal plate. The whole structure of the mesencephalon may be delineated by these veins in combination with the other veins of the mesencephalon. They may be of diagnostic value in the early recognition of the brain stem lesions.

Radioimmunoassay of 16alpha-hydroxy-dehydroepiandrosterone and its sulfate

A simple and reliable radioimmunoassay for plasma 3beta, 16alpha-dihydroxy-5-androsten-17-one(16alpha-OH-DHEA) and its sulfate has been developed. The antiserum against 16alpha-OH-DHEA and its sulfate (16alpha-OH-DHEA-3-sulfate) was produced in rabbits immunized with 16alpha-OH-DHEA-3-succinate-bovine serum albumin. This antiserum reacted well with both 16alpha-OH-DHEA and its sulfate and only slightly cross reacted with DHEA and its sulfate. The coefficient of variation (C.V.) of the intra assay was 10.26% for 16alpha-OH-DHEA and 12.32% for 16alpha-OH-DHEA-S. The C.V. of the interassay were 14.34% for 16alpha-OH-DHEA and 15.64% for 16alpha-OH-DHEA-S. The umbilical artery concentrations for 16alpha-OH-DHEA and 16alpha-OH-DHEA-S were 7.20 +/- 6.71 ng/ml and 4490 +/- 2140 ng/ml, and the umbilical vein concentrations were 14.20 +/- 11.27 ng/ml and 2970 +/- 1450 ng/ml respectively.

Chemical composition and properties of soybean beta-amylase

The molecular weight of soybean beta-amylase [EC 3.2.1.2] was determined to be 57,000 daltons by the sedimentation equilibrium method, and the enzyme was found to consist of 494 amino acid residues. No difference was found in molecular weight or composition between two components of beta-amylase separated by ion-exchange chromatography. The N-terminus of the enzyme was not detectable by the fluorodinitrobenzene method or phenylisothiocyanate method, and the C-terminus was determined to be alanine by the carboxypeptidase [EC 3.4.12.2] method. Five half-cystine residues were found in the form of cysteine; all the sulfhydryl groups could be titrated by p-chloromercuribenzoate after denaturation of the enzyme with guanidine hydrochloride, but only some in the native enzyme. The rates of mercaptide formation of these groups were dependent on pH and were different from each other, all being much lower than the rate for the free sulfhydryl group in mercaptoethanol. Differential titration experiments at different pH's and in the presence of maltose showed that mercaptide formation by only one sulfhydryl group caused loss of activity, and the reaction was accompanied by changes in the environment around aromatic side chains in the enzyme, which were detected by difference spectra and fluorescence emission spectra. These facts suggest that modification of the sulfhydryl groups causes a conformational change of the enzyme. Some preliminary crystallographic data for crystals formed at pH 4.0 were obtained, and inactivation by heavy metal salts was examined in relation to the preparation of isomorphous heavy atom derivatives.

Haemangioma of median nerve causing carpal tunnel syndrome

A case report of an intraneural haemangioma which occurred in a nineteen year old girl, with an acute clinical course. Intraneural haemangioma is a rare condition, but may be another cause of carpal tunnel syndrome.

An electron microscopic study on the blood-optic nerve and fluid-optic nerve barrier

Utilizing horseradish peroxidase as a tracer, electron microscopic studies were done on the blood-optic nerve and fluid-optic nerve barrier to the peroxidase diffusion. Following intravenous injection the peroxidase was observed to fill the lumen of the capillaries of the laminar, prelaminar and orbital portions of the optic nerve but there was no penetratation of the capillary walls. The obstruction of the tracer diffusion out of capillary walls was attributed to the tight junctions between the endothelial cells. Peroxidase penetration was also absent in the capillaries of the pia and dura mater, however, was observed in pinocytotic vesicles of the endothelial cells. Lateral diffusion from the surrounding choroid into the optic nerve was detected but diffusion from the prelaminar optic nerve into the juxta-optic nerve retina was prevented by the Kuhnt intermediary tissue. Tight junctions which prevented peroxidase diffusion were found between the glial cells of the Kuhnt tissue, and this tissue was the barrier between the prelaminar optic nerve and the juxta-optic nerve retina. Peroxidase which was given into the lateral ventricle of the brain appeared in the subarachnoidal space around the optic nerve and penetrated freely into the optic nerve. The pial surface of the optic nerve possess no barrier activity. Peroxidase could be traced along the intercellular space between glial cells and optic nerve fibers. The basal lamina of the optic nerve capillaries was filled with peroxidase but diffusion into the capillary lumen was obstructured by the tight junctions between the endothelial cells.

Crystallization and preliminary x-ray investigation of soybean beta-amylase

Beta-Amylase [1, 4-alpha-D-glucan maltohydrolase, EC 3.2.1.2] has been purified from defatted soybean meal by fractional precipation with ammonium sulfate, ion-exchange chromatography on CM- and DEAE-Sephadex and gel filtration chromatography on Sephadex G-100. Two different components of beta-amylase were crystallized from ammonium sulfate solutions, and the homogeneity of each preparation was confirmed by sedimentation and disc electrophoretic analyses. Both components of soybean beta-amylase formed large single crystals (trigonal crystal system) from 40--50 per cent saturated ammonium sulfate solution buffered at pH 5.4 on dialyzing concentrated protein solution in the apparatus of Zeppezauer et al. Preliminary X-ray diffraction data gave a hexagonal lattice with unit cell dimensions a=86.1 A and c=144.4 A. The space group corresponds to P3121 or P3221, and one asymmetric unit contains one molecule of beta-amylase, assuming a crystal density of 1.25 g/ml and a molecular weight of the enzyme of 60,000 daltons. In this case, the crystal has a volume of 2.53 A-3 per atomic mass unit, and the percentage of protein in the crystal is about 52.